Q: In the broadcast segment, a crow demonstrated tool-making. Have you seen that level of sophistication in birds other than corvids? Thank you for your participation in this excellent program and congratulations on all your accomplishments. Jo Linda Finne
Erich Jarvis: Dear Jo Linda,
The crow studies you mention were conducted by Alex Weir at Cambridge University. The crows and other corvid songbirds, such as jays, generally show sophisticated behaviors. I do not know of other avian species that have shown spontaneous tool use. This does not mean that such studies have not been conducted. I just have not followed that area of research in great detail. However, chickens pecking levers in an operant training test to get a food reward, that may be considered one form of tool use.
Q: I was fortunate to hear a story on NPR about how a particular bird (I fail to remember what kind) learned its song. The typical call of this bird was broken into five parts (A, B, C, D, E), and scientists taught one of these birds this same call but in reverse (E, D, C, B, A)! When watching your story on NOVA scienceNOW and being a musician I remembered this and wondered: could a bird, such as the one in the NPR story, learn multiple and more complex variations of its song? Brent Scheihagen, Austin, Texas
Jarvis: Dear Brent,
There are three vocal learning bird species: songbirds, parrots, and hummingbirds. Songbirds are the most commonly studied, and thus on NPR you probably heard something about a songbird species. A number of songbirds can be taught to produce song syllables in reverse and in other orders, as long as you train them at an early age before their critical period where learning abilities thereafter decrease.
Unlike primates with one vocal learning species—humans, for example—among songbirds there are thousands of species with vocal learning. Each species has variations on how vocal learning occurs. Thus, some species, such as the mockingbird and canary, can learn multiple songs with complex variations. Others, like the zebra finch, learn one song and produce little variation in the sequence of their syllables. Still others, such as crows (which are songbirds) and a number of parrot species, have a great deal of variation such that the amount of variation has been almost impossible to quantify. The lesson of these studies is that by studying one species—humans—you miss out on understanding the variation that exists in nature, including for something that is the substrate for human speech.
Q: Dr. Jarvis: I'd like to congratulate you on your life's accomplishments as well as your devotion to the momentum of science rather that the ego of it all. Your interview on NOVA scienceNOW greatly inspired me as I am now faced with a similar, albeit scaled down, version of the decision you made between science and dance. My question is whether or not you currently have plans to write a book from your perspective? Your story makes me think of Georgetown scientist Candance Pert's book Molecules of Emotion. I think thousands of young aspiring scientists could benefit greatly from your story. Thank you, Rob Smith, New York, New York
Jarvis: Dear Rob,
Since a story about my deceased father appeared in the New York Times in 1989 and every time since then when something about my life and work is presented in the public media, I receive requests to write a book or have someone write one for me. Except that one time in 1989, I have not entertained the request, because I am still in the progressive part of my career and life. It is possible that such a book would inspire young minds to pursue science and related careers, and I am honored to read that you think this is possible. But I can only do that now if it would not take an extraordinary amount of time and would not prevent me from making the discoveries I am seeking, or if someone made me an incredible offer. That has not happened yet. But thanks for the thought.
Q: I saw your work explained on NOVA scienceNOW. It should have been obvious to people that birds have intelligent brains. African grey parrots can learn to speak, and they can be taught to tell color, and even to express themselves. And from what I observed on NOVA scienceNOW, some birds are capable of creating simple tools. But what about the other kinds of birds that are incapable of doing things like this? For example, a crow can make tools to obtain food but a pigeon can't. Why? Why is the parrot smarter than the finch? Is it brain size, the way they use their brains, or does the parrot have something the finch doesn't? I would like so much to know this. I would be grateful to hear from you. Anonymous, 10th grade, Waterbury, Vermont
Jarvis: Dear 10th grader,
It is obvious to some people that birds have intelligent behavior. It has been proven in scientific studies and in everyday observation over many years. In fact, an argument can be made that having a brain means that you have intelligent behavior, regardless of whether you are a bird, mammal, reptile, or otherwise. But this is not the way many people think. There is something inherent in our human psyche that wants to make nonhumans "lower" in intelligence, and for us to form a scale of intelligence such that some species would be considered not intelligent. This is the source of the terms lower and higher animals.
In fact, it is very difficult or almost impossible to make such a scale. Yes, a crow can make tools, and as far as I know, this has not been observed in pigeons. But pigeons have incredible visual memories and abilities, including the ability to learn how to distinguish different styles of impressionistic paintings. Chickadees, which are a type of songbird, can store over 3,000 seeds in the forest, and during the winter they remember where they put them and retrieve most of them. A parrot so far as I know has not been observed to do this, yet a number of parrot species can imitate some human speech.
So what is the answer? Different species have different behavioral capacities that vary in sophistication. Part of the sophistication is controlled by the size of the brain area that controls that behavior relative to the size of the rest of the brain; chickadees have a larger hippocampus than other birds, which they use for food- storing behavior. However, brain size is not the main driving factor behind these complex behaviors. Instead, neural connectivity appears to be the driving force. Parrots and other vocal learning birds have forebrain connections to motor neurons of the brainstem for controlling production of sounds. Nonvocal learning species do not have this connection from the forebrain, regardless of how big or small the size of their brain. This is still an area of active research, and it may be something you would be interested in studying one day.
Q: How did you find what you wanted to do in life? I don't have any idea, so I thought I could get some advice. Robert Townsend, Lakeside High School 9th grade, Atlanta, Georgia
Jarvis: Dear Robert,
I found out what I wanted to do in life through the experience of trying something that seemed interesting to me; then if I liked it, I pursued it with a passion. You never know if you really like something until you give it your all. My advice is that when you are not sure of you want to do in life, then don't spend too much energy thinking about it. This will drive you crazy. Instead, pick something, even if you are not completely happy with your pick, and work on it with a passion. At some time in the future, should you decide that it was not for you, then move onto the next thing and try it with a passion. If you discover that it is for you, at least you did not waste your time mulling over what you want to do. You are going to be 18, 21, 25, 30, etc., one day. These are critical years too. Don't waste your time. If you try this approach, you can't go wrong, because you will always accomplish something. And that is the main point: accomplish something! Accomplish something good, of course. Who cares what it is?
Q: My personal research shows that when we enter the right-brain style of thinking we can tap into wisdom far beyond what we already know. Do you think your dancing, which is essentially right-brain activity, helps you to tap into this inspiration during your usually left-brain-dominated scientific work? And, if so, do you ever dance in the lab in order to trigger that connection?! June-Elleni Laine, London England
Jarvis: Dear June-Elleni,
These are interesting questions. That is, I had to think more about them to figure out how to answer them; there is not much solid science known on how to answer them. So, I'll give you a qualitative answer. The right brain, which controls mainly the left side of the body, is considered to be involved in more artistic and creative functions. This is why left-handed people are considered artistic by some investigators. The left brain, which controls mainly the right side of the body, is considered to be more involved in everyday logical functions.
So where do science and dance fall? Science in my mind is actually a beautiful combination of the two. This is because discovering new things about nature requires a great amount of creativity. I envy my left-handed scientific colleagues. Science also requires a great deal of logical reasoning, the right brain. For dance, I am not sure what side of the brain would be dominant. Since dance requires good muscle coordination, I would imagine that the left side is heavily involved because most of us are right handed and right legged dominant.
So, do I incorporate my artistic dance training into my science? You bet. But I have not danced in the lab or on top of the bench tops. Instead, I use the artistic knowledge that I gained as a dancer to help my science—this knowledge includes creativity, discipline, hard work, and stamina. I will try dancing in the lab. If it works, I will get back to you.
Q: Some birds, such as parrots, have the ability to reproduce sounds they learn from humans, thus creating actual words. Do they understand anything—even just a tonal nuance—about the content of what they are saying, or do they simply mimic us? Michael Cooper, Dallas, Texas
Jarvis: Dear Michael,
It is difficult to peer into the mind of any nonhuman animal and ask, "Do you know or attach meaning to the sounds that you vocalize?" But scientists have been asking just this exact question, and the evidence that we can intepret suggests that animals that mimic can attach meaning to the sounds. The most well known studies have been done by Irene Pepperberg, who found that African grey parrots do refer to objects and even ideas with their learned human speech sounds. Whether this means that all birds that mimic human speech know the meaning or make up novel meanings to the sounds they imitate cannot be said.
However, it is hard to imagine what the purpose of mimic without meaning would be useful for. Even chimpanzees, vervet monkeys, and chickens, which cannot mimic vocalizations, use innate sounds with meaning. Some innate sounds mean an eagle above, a snake on the ground, or food in a tree. These were studies done by Peter Marler and his students. So if animals that produce innate-only sounds have meaning in their vocalizations, then it does not seem to be a giant leap that vocal learners place meaning into their mimicked sounds—species- and nonspecies-specific.
Q: Dear Dr. Jarvis,
This is a bird flu-related question. Does a sick bird vocalize its distress? Could a method be devised to record and digitally analyze bird vocalizations in order to pick up on sickness at the earliest stages of disease?
With great curiosity and best regards, Leon Akselrad, Saratoga, California and Yoqneam Elit, Israel
Jarvis: Dear Leon,
This is a very useful question. I can think of sneezing, but I never observed a bird to sneeze before. But who knows? One thing clear to me is that a sick bird does not vocalize much. A hungry bird will make distress calls. Software does exist that can recognize specific sounds. This includes speech-recognition programs. I am not sure of the feasibility of this for detecting birds that become sick with bird flu. But it does sound like a good idea worth testing.
Q: Are you one of the researchers studying the FoxP2 gene? If so, do you think studies of this gene will one day soon help my four-year-old cousin, who has verbal appraxia? Are there any birds that suffer these kinds of speech disorders? Anonymous
Jarvis: Dear Anonymous,
Yes, I am one of the researchers that studied the FoxP2 gene. My colleagues and I published a paper in the Journal of Neuroscience in 2004. We found that FoxP2 is up-regulated in the songbird basal ganglia vocal nucleus (called AreaX) at times when vocal learning occurs and is down-regulated to basal levels when vocal learning is complete. It will be a long while before we can perform gene manipulations in humans to control FoxP2 and other genes associated with language functions. Thus, we cannot help your four-year-old cousin now with such an approach. He or she will have to be treated by other means. I do not know of any birds with song appraxias. Then again, I do not think it has been searched for. Keep searching for information for your cousin.
Q: Dear Erich,
I like to walk in the woods and sit in the park and watch and listen to birds. Is there anything you would suggest that I watch/listen for as a simple layperson's observational experiment that might show me something about birdsong or behavior? Amani Walther, New York, New York
Jarvis: Dear Amani,
One of the open questions about birds with vocal learning abilities is whether they use their learned vocalizations for more than attracting mates and defending territories. In this regard, it would be useful to observe what additional context the birds use their vocalizations for. Will you hear a certain type of vocalization when a particular species finds a food source? When it fights? When it encounters another bird? Use your tape recorder to record them, and then play back the vocalizations to test your theory. Determine if the birds respond as you would predict. If you have some extra cash, purchase a digital recorder, parabola, headphones, and a microphone that can record vocalizations at least within the 0.5-20 Khz range. Make sure the speaker can play sounds back within this range as well.